The present invention relates to a display device with a backlight, and more particularly to a liquid crystal display device using a field sequential system.
A display device includes a TFT substrate in which pixels each having a pixel electrode, a thin film transistor (TFT), and the like are arranged in a matrix form. Further, there is provided a counter substrate opposite the TFT substrate, in which color filters and the like are formed at positions corresponding to the pixel electrodes of the TFT substrate. Further, a liquid crystal is interposed between the TFT substrate and the counter substrate. Then, an image is formed by controlling the transmittance of light through each pixel by the liquid crystal molecules.
The liquid crystal display device can be made thin and lightweight, and is thus widely used in a variety of fields. The liquid crystal does not emit any light of its own, so that a backlight is provided on the back side of a liquid crystal display panel. There is a technique for increasing the amount of light in the perpendicular direction to the surface of the liquid crystal display panel by using a prism sheet, and the like, in order to increase the efficiency of the use of the backlight.
The viewing angle characteristics are a problem for the liquid crystal display device. Japanese Unexamined Patent Application Publication No. 2000-214456 describes a structure that can achieve high viewing angle characteristics and high contrast by means of a collimated backlight with collimating means for the back light.